Faculty of Agriculture, Food Engineering Department, Cukurova University, Adana, Turkey.
Faculty of Engineering, Food Engineering Department, Adana Alparslan Turkes Science and Technology University, Adana, Turkey.
Yeast. 2020 Sep;37(9-10):449-466. doi: 10.1002/yea.3500. Epub 2020 Jun 22.
In the present study, a total of eight sourdough samples were collected from three different bakeries at two different times in Turkey. Also, laboratory-scale sourdough production was conducted by daily back-slopping for 7 days. Microbiological and chemical properties of the sourdoughs were investigated. Yeast species in the sourdoughs were identified by subjecting all presumptive yeast cultures to internal transcribed spacer region amplification of the 5.8S rRNA gene, restriction fragment length polymorphism analysis using Hae III, Hha I, and Hinf I endonucleases, and sequence analysis of the D1/D2 domain of the 26S rDNA gene. A total of seven profiles were determined according to the restriction fragments. Totally, 148 yeast isolates were identified at the species level (≥400 bp, 99% identity) as Saccharomyces cerevisiae (106), Kazachstania bulderi (11), Pichia fermentans (nine), Pichia membranifaciens (eight), Kazachstania servazzii (seven), Kazachstania unispora (four), and Hanseniaspora valbyensis (three). Although collected sourdoughs were produced without using baker's yeast, S. cerevisiae was the most frequently isolated yeast species. This can be related to the contamination of the bakery environment with commercial baker's yeast during the production of other bakery products. The pH and acidity levels of the collected sourdough samples ranged from 3.71 to 3.96 and 6.78 to 23.93 mL 0.1 N NaOH/10 g dough, respectively. Mean values of the content of maltose + sucrose, glucose, fructose, lactic acid, and acetic acid were 2.43, 1.57, 2.67, 7.30, and 1.40 g/kg, respectively. Due to the artisan and region-dependent handling of the sourdough, different biochemical patterns were observed among the collected samples.
在本研究中，共从土耳其的三家不同面包店在两个不同时间采集了 8 个酸面团样本。此外，通过每天回种进行了实验室规模的酸面团生产，持续了 7 天。研究了酸面团的微生物和化学性质。通过对所有假定的酵母培养物进行内部转录间隔区（ITS）区域扩增、使用 Hae III、Hha I 和 Hinf I 内切酶进行限制片段长度多态性分析以及对 26S rDNA 基因的 D1/D2 结构域进行序列分析，鉴定了酸面团中的酵母物种。根据限制片段确定了 7 种图谱。总共在物种水平上鉴定了 148 株酵母分离株（≥400 bp，99%同源性），分别为酿酒酵母（106）、库尔氏毕赤酵母（11）、发酵毕赤酵母（9）、膜毕赤酵母（8）、司格毕赤酵母（7）、单一毕赤酵母（4）和瓦氏汉逊酵母（3）。尽管收集的酸面团是在不使用面包酵母的情况下生产的，但酿酒酵母是最常分离到的酵母物种。这可能与在生产其他面包店产品时，面包店环境受到商业面包酵母的污染有关。收集的酸面团样品的 pH 值和酸度范围分别为 3.71 至 3.96 和 6.78 至 23.93 mL 0.1N NaOH/10 g 面团。麦芽糖+蔗糖、葡萄糖、果糖、乳酸和乙酸的含量平均值分别为 2.43、1.57、2.67、7.30 和 1.40 g/kg。由于酸面团的手工和地区依赖性处理，收集的样品之间观察到不同的生化模式。
